Devices are apparently known, in which powder is fed to the region of the focal spot by means of a transport gas. However, the powder is applied in a manner displaced anyhow in relation to the geometric longitudinal axis, so that not all of the volume of powder is exposed to the same process conditions during the coating. This results in inhomogeneities. Depending on whether the device--and thus the laser beam--moves forwards, backwards, sideways or the like, the results of the operation are different. If, for example, a type of blast pipe were used as the feeding device, then this pipe must blast obliquely in relation to the geometric longitudinal axis. This leads to preferred directions of the applied coating, which are unfavorable. If an annular nozzle were provided around the geometric longitudinal axis, then the laser beam is, so to speak, enveloped by the powder. In this case, only the lagging powder then passes into the laser beam. In this case, the leading or laterally fed volume of powder undergoes an entirely different treatment, or possibly even no treatment whatsoever.
A further disadvantage is that the loss of powder is relatively great, as it is blown away without having been deposited as a coating on the surface.